If you have children, it is your duty to sit down with them and let them watch these videos. Inform them of the dangers of social media / the internet.
Parents feel that children are safe if they play on their tablets/laptops when they're at home. But would you let your child play with a 40 year old stranger? In many online games, that is exactly what is happening.
It is not only your right to know about their online activities. It is your duty!